Method of processing sheet-like workpieces in a strip-shaped manner

ABSTRACT

The invention relates to a method for machining platelike workpieces in a striated manner, whereby, in work steps, the material plate is machined by a controlled linear unit in a striated manner and always in the same X-axis direction. The invention also relates to a device for carrying out said method.

The invention relates to a method of processing sheet-like workpieces ina strip-shaped manner, the material sheet being worked in a strip-shapedmanner in working steps by means of a controlled linear unit and alwaysin the same X-axis direction.

German Patent 508 474 discloses a method of producing parallel cut orhole rows one after the other in blank material sheets. The materialsheet, with the one longitudinal edge which runs parallel to the feeddirection being placed against a stop strip, is first of all providedwith a first cut row, is then removed completely from the region of thepress and, for the purpose of producing the second and the following cutrows, in each case after being displaced in the sheet transversedirection, is fed again to the tool and always in the same feeddirection. For producing the respectively second, third and followingcut rows in the material sheet, the spacing of the rows is effected byplacing the one original sheet longitudinal edge against a stop stripwhich can be adjusted at the same time in each case, so that finally theentire original material sheet is pierced with cut or hole rows in themanner described above and can be discarded.

On the other hand, however, it is also possible,when each row is stampedor cut out, for the scrap (stamped grid) which is being produced or hasbeen produced to be cut off from the original or the previouslongitudinal edge at a distance corresponding to the spacing of therows. In this way, the original material sheet, each time thestamped-grid strip is dispensed with, is reduced down to the last strip,which is then discarded after the stamping of the hole rows.

This prior art has the disadvantage that in each case only a singlematerial sheet is worked in cut rows, the material sheet alreadyprovided with a cut row being taken completely out of the region of thepress in each case and passing via a relatively large distance behindthe press in the same feed direction again into the region ofthe-cutting tool, with the result that considerable time is needed forworking a material sheet.

Furthermore, PCT/SE 93/00820-WO 94/08740 discloses a method and anapparatus for processing sheets on C-frame presses, this apparatusprogressively working a material sheet in a strip-shaped manner in theX-direction in a horizontal processing plane. After a strip has beenprogressively processed from the metal sheet and subdivided intosections, the respectively remaining residual grid is in each casesubsequently separated and removed section by section. After this, theremaining residual sheet is returned at the level of the bottom toolposition above the table fixed to the frame into the initial position,is displaced transversely to the processing direction by one stripwidth, and is progressively processed again in the X-direction.

This type of sheet processing enables a single metal sheet to be workedin a strip-shaped manner in steps from the selected first feed side ineach case, so that, as a result of the return, larger time intervalsinevitably occur in each case in which no cut parts are produced. A highdischarge sequence of workpieces cannot be achieved by means of thismethod either.

The object of the invention, then, is to propose a method of processingsheet-like workpieces in a strip-shaped manner for high workingfrequencies.

SUMMARY OF THE INVENTION

According to the invention, this object is achieved in terms of themethod by the features of patent claim 1.

In this case, the processing method is based on the fact that at leasttwo material sheets are always alternately and cyclically processed in astrip-shaped manner in working steps and always in the same X-axisdirection. In this case, a first material sheet is worked cyclically ina strip-shaped manner in the X-axis direction at its bottom side end,and a further material sheet follows the first material sheet in thesame X-axis direction. After the last processing step on the strip,being processed, of the first material sheet has been effected, therespectively bottom side is directly worked from a second material sheetin a strip-shaped manner in the same X-axis direction.

The first material sheet, reduced by one material strip, is now returneddirectly at the processing space against the X-axis feed direction intothe initial position and is corrected in the Y-axis direction in thestrip depth to be worked. This first material sheet, which has thus beenreturned, will now in turn directly follow the last working step of thesecond material sheet, a further strip-shaped part being workedcyclically from this first material sheet. This processing ofstrip-shaped parts of material sheets in always the same X-axisdirection is continued until one material sheet has only a laststrip-shaped material-sheet part, which, as described according to theinvention, is processed cyclically. A new material sheet then followsthis respectively last strip-shaped material-sheet part of eachcyclically worked material sheet, and this new material sheet thenfollows the material sheet, still being processed, in the X-axisprocessing direction.

Thus it is possible for the first time to cyclically work materialsheets in a strip-shaped manner in always the same X-axis direction athigh working frequencies without time losses.

The material sheet prepared for the sheet processing, before a strip isworked cyclically, is advantageously moved laterally into the processingplane, is processed, and is moved out of the processing plane againafter the separation of the residual grid.

A further design of the invention is seen in the fact that the materialsheets to be worked cyclically, including the last strip-shaped part ofa material sheet, are in each case returned laterally outside theprocessing plane against the X-axis direction of the processing into therespective ready position.

In an especially advantageous manner, the invention is characterized inthat directly following the strip-shaped end of each material sheet,including the last strip end of a material sheet, in a cyclical manneris in each case a start of the following material sheet, including thestrip-shaped start of a worked material sheet.

BRIEF DESCRIPTION OF THE DRAWINGS

The Invention is described in more detail below with reference to anexemplary embodiment:

In the drawings:

FIGS. 1a to e,

FIGS. 2f to j, and

FIGS. 3k to o show the schematic sequence of the method of processingsheet-like workpieces in a strip-shaped manner.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The method according to the invention for processing material sheets isshown schematically from FIG. 1c to FIG. 3o in individual method steps.In all the FIGS. 1a to e, 2 f to j and 3 k to o, for the sake ofclarity, the material sheets are merely shown symbolically in individualstrip-shaped parts.

In principle, however, the connection of a lowermost strip-shapedresidual grid is always severed only when the last cut/drawn part hasbeen produced.

FIGS. 1a, 1 b illustrate, as it were, a single starting sequence for amaterial sheet 10 by means of the feed device 1, during which startingsequence cut/drawn parts 4 are cut out of a first bottom material-sheetstrip 11 by means of the cutting/drawing tool 3.

In the process, the remaining residual grid of the material-sheet strip11, during. each stroke of the cutting/drawing tool 3, by means of atool cutting-edge part, is separated from the remaining material sheet,which then still consists of the strip parts 12, 13, 14, 15, and isremoved as an entity from the region of the processing with the lastseparating stamping of the material-sheet strip 11, in other words whenthe connection with the material sheet then remaining is severed.

FIG. 1a therefore represents a single ready position of the two materialsheets 10, 20 being processed, which are each provided at the start ofsheet processing, in order to provide a positioning difference orspatial difference for the holding and feed devices 1, 2.

In FIG. 1b, therefore, a first material sheet 10 is fed to the left tothe tool 3 in arrow direction 5 by means of a holding and feed device 1,while the second material sheet 20 remains located in the waitingposition with holding and feed device 2.

After the processing of the first lowermost double row of cut/drawnparts 4 from the material-sheet strip 11, the residual grid consistingof this material-sheet strip is removed. The first material sheet 10,according to FIG. 1c, now consists of the material strip parts 12, 13,14 and 15.

The arrow guide 6 in FIG. 1c illustrates, in this schematicrepresentation, that the sheet size reduced by one material strip, afterleaving the cutting/drawing tool 3 on the left side, performs apositioning movement away from the processing plane, returns into theinitial position and is adjusted by one material-sheet strip. Thematerial strip 12 to be processed is therefore in front of thecutting/drawing tool 3 and the first material sheet 10 is thus workedagain.

The processing method according to the invention starts at this point byin each case two material sheets 10, 20 being alternately workedcyclically in a strip-shaped manner in the X-axis direction.

According to FIG. 1d, the material-sheet strip 12 is worked from thematerial sheet 10 in arrow direction by producing cut/drawn parts 4,e.g. can lids, is completely separated from the remaining material sheetand is discarded as residual-grid strip.

In the same X-axis direction, directly with the last stamping of thecut/drawn parts 4 from the material-sheet strip 12, the material sheet20 with the material-sheet strip 21 is fed to the cutting/drawing tool 3and subsequently worked cyclically in a strip-shaped manner.

FIG. 1e illustrates that the remaining material sheet 10, which nowconsists of the material-sheet strips 13, 14, 15 and is returned againin arrow direction 7 a directly past the working space below or behindthe material sheet 20 against the X-axis feed direction into a readyposition, while the lowermost material-sheet strip 21 is workedcyclically from the second material sheet 20 in the X-axis direction.

FIG. 2f, on the left side, illustrates the completion of the cyclicalworking of the material-sheet strip 21 from the material sheet 20, whilethe material sheet 10 is returned against the X-axis processingdirection below or behind the material sheet 20 being processed, isadvanced up to the working space according to arrow direction 7 b, isadjusted by one material-sheet strip depth in the Y-axis direction anddirectly follows the material sheet 20 in the X-axis direction in thecutting/drawing tool 3, and a first stamping stroke of the materialstrip 13 is carried out.

FIG. 2g illustrates that the lowermost material-sheet strip 13 is workedcyclically from the material sheet 10, while the material sheet 20 isbrought back again according to arrow direction 8 a in front of or abovethe material sheet 10 against the X-axis feed direction past the workingspace into a ready position.

In FIG. 2h, on the left side, the sheet strip 13 is worked cyclicallyfrom the material sheet 10, and the material sheet 20 is adjusted by afurther strip depth in the Y-axis direction according to the arrowregime 8 b, so that the sheet strip 22 is cyclically processed. At thispoint, the method according to the invention for processing materialsheets has been carried out by virtue of the fact that in each case twomaterial sheets 10, 20 are worked alternately in a strip-shaped manner.

In FIG. 2i and FIG. 2j, the sequence already described according to thearrow regime 7 a, 7 b, as presented according to FIG. 1e and FIG. 2f, ismerely repeated, with the difference that, firstly, a material sheet 10,as bottom or rear material sheet, assumes the leading role in theworking space of the cutting/drawing tool 3, and after this the materialsheet 20 is made to follow up, whereas the material sheet 20, in frontof or above the material sheet 10, subsequently takes the leading rolein the working space of the cutting/drawing tool 3 according to thearrow regime 8 a, 8 b, see FIG. 3k and FIG. 3e. With each processingsequence, the respective material sheet is alternately reduced by onebottom material-strip part, so that, finally, according to FIG. 3m, onthe right side, the material sheet 10 consists only of the lastmaterial-strip part 15.

This last material strip 15 is now advanced up to the working region ofthe cutting/drawing tool 3 according to arrow regime 7 a, 7 b by meansof the feed device 1 and is taken over by a feed device 9, which thenmoves the remaining sheet strip cyclically through the cutting/drawingtool 3 in the X-axis direction. This processing operation is shownschematically in FIG. 3n.

From FIG. 3l, a new sheet 10 is prepared, so that the feed device 1,after it has delivered the last strip-shaped part 15 to the feed device9 according to FIG. 3n, can take over a new material sheet 30 accordingto FIG. 3o. As described above, the processing sequence of the materialsheet 20 with the material-sheet strip 23 and 24 takes place accordingto the arrow regime 8 a, 8 b, so that ultimately, according to FIG. 3o,the material-sheet strip 25 still remaining can also be taken over bythe feed device 9 and is worked cyclically, and consequently the feeddevice 2 can likewise take over a new material sheet. By means of themethod steps described in detail, it is possible for the first time toalternately work material sheets cyclically in a strip-shaped manner inalways the same X-axis direction at high working frequencies withouttime losses.

List of Designations

1 Feed device of the workpiece sheet 10

2 Feed device of the workpiece sheet 20

3 Cutting/drawing tool

4 Cut/drawn part—e.g. can lid

5 Arrow direction according to FIG. 1a

6 Arrow direction according to FIG. 1c

7 a Arrow direction according to FIG. 1e

7 b Arrow direction according to FIG. 2f

8 a Arrow direction according to FIG. 2g

8 b Arrow direction according to FIG. 2h

9 Feed device for respectively last material-sheet strips

10 First material sheet

11 Material-sheet strip of the material sheet 10

12 Material-sheet strip of the material sheet 10

13 Material-sheet strip of the material sheet 10

14 Material-sheet strip of the material sheet 10

15 Material-sheet strip of the material sheet 10

20 Second material sheet

21 Material-sheet strip of the material sheet 20

22 Material-sheet strip of the material sheet 20

23 Material-sheet strip of the material sheet 20

24 Material-sheet strip of the material sheet 20

25 Material-sheet strip of the material sheet 20

30 Third material sheet

We claim:
 1. A method of processing material sheets, which comprises:providing material sheets each having a bottom sheet end with a bottomsheet margin; processing the material sheets in strips in each case atthe bottom sheet end in working steps in an X-direction, and therebystamping out cut parts from the respective lowermost material-sheetstrip and ejecting the cut parts and forming a stamped-grid strip;thereafter progressively cutting respective stamped-grid strips from thematerial sheet parallel to a bottom sheet margin and removing the stripgrid after complete separation; wherein the processing step comprisesalternately processing two material sheets in strips, with a firstmaterial sheet being worked cyclically along a strip in the X-direction,a second material sheet being fed in the X-direction, and the secondmaterial sheet being subsequently worked cyclically along a strip, whilethe first material sheet, now reduced by one material strip, is returneddirectly past a processing space counter to the X-direction into a readyposition, is adjusted in a Y-direction by a strip depth to be worked,and then cyclically follows the second material sheet in theX-direction, and wherein a further strip is worked cyclically from thefirst material sheet, and a new material sheet to be processed is madeto follow the respectively last strip of each worked material sheet inthe X-axis direction.
 2. The method according to claim 1, whichcomprises, before a strip is worked cyclically, moving each new materialsheet laterally into the working space and laterally out of the workingspace after the separation of the stamped-grid strip.
 3. The methodaccording to claim 1, which comprises returning the material sheets,including the respectively last strip, laterally outside the workingspace against the X-axis direction into the ready position.
 4. Themethod according to claim 1, which comprises causing a start of afollowing material sheet, including the strip-shaped start of a workedmaterial sheet, to directly follow in a cyclical manner the strip-shapedend of each material sheet, including the respectively last strip end ofthe material sheet.